99
pressed air. The simplest forifiQf sprjjeir S3f Stilish <3aai?
acter is a bottle fitted with a q^e£Sai tube and an india ^ /
rubber ball or bag, sucih as is us^^rj^hairdressers. SuchX,' ^
a sprayer answers all right for ^r^y^^--sniall_4^ff^r '^j/^
Another and still more useful sprayer^x^^iXrf^i^1?^^^
is a brass or nickel apparatus, fitted with an air pump-and
a chamber capable of holding four pints of liquid. In this
case the insecticide or fungicide is first poured in and
the orifice securely closed and then a few strokes given
by the air pump to charge the apparatus with compressed
air. By turning a tap attached to the delivery nozzle
the air then forces out the liquid in a fine spray.
Yet another type of sprayer is the hand pump. Thds
consists of a suction tube of metal or rubber placed in
an ordinary pail, a delivery metal or rubber tube, and a
piston fitted with a crutch or a metal crank handle.
At the base of the main cylinders is a foot rest for the
operator to stand on whilst using the piston. One hand
in this case works the latter, while the other is employed
in holding and directing the spraying tube and nozzle.
Such an apparatus is suitable for spraying dwarf fruit
trees, roses, or for syringing wall fruit trees.
Still more useful for general spraying potato crops is
the knapsack sprayer. There are many different kinds on
the market. They are -made of copper or tinned copper, and
fitted with straps so that they can be carried on the back
of the operator. Their average weight when empty is
about i4ilbs., and they hold 3^ gallons of liquid. They
are fitted with air chambers and internal or external air
pumps. The pumps in this case are worked by the
operator by one hand, while the other is employed in
directing the delivery tube and nozzle. Each is provided
with a short length of hose and a brass lance 3 feet long
to which the nozzle is attached. For tall trees a bamboo
lance 5 feet lo^g is used. Some forms of knap-sack
sJprayers are worked by compressed air forced into the
air chambers beforehand. They are fitted with a
pressure gauge, and also a safety value. These are
termed " pneumatic sprayers." It is only necessary in
their case to turn a tap to discharge the fluid.
Care of Spraying Machines.—All machines im-